package mapreduce;
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;
public class MyAverage{
	public static class Map extends Mapper<Object , Text , Text , IntWritable>{
    private static Text newKey=new Text();
    public void map(Object key,Text value,Context context) throws IOException, InterruptedException{
    String line=value.toString();
    System.out.println(line);
    String arr[]=line.split("\t");
    newKey.set(arr[0]);
    int click=Integer.parseInt(arr[1]);
    context.write(newKey, new IntWritable(click));
    }
    }
    public static class Reduce extends Reducer<Text, IntWritable, Text, IntWritable>{
    public void reduce(Text key,Iterable<IntWritable> values,Context context) throws IOException, InterruptedException{
        int num=0;
        int count=0;
        for(IntWritable val:values){
        num+=val.get();
        count++;
        }
        int avg=num/count;
        context.write(key,new IntWritable(avg));
        }
        }
        public static void main(String[] args) throws IOException, ClassNotFoundException, InterruptedException{
        Configuration conf=new Configuration();
        System.out.println("start");
        Job job =new Job(conf,"MyAverage");
        job.setJarByClass(MyAverage.class);
        job.setMapperClass(Map.class);
        job.setReducerClass(Reduce.class);
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(IntWritable.class);
        job.setInputFormatClass(TextInputFormat.class);
        job.setOutputFormatClass(TextOutputFormat.class);
        Path in=new Path("hdfs://localhost:9000/mymapreduce4/in/goods_click");
        Path out=new Path("hdfs://localhost:9000/mymapreduce4/out");
        FileInputFormat.addInputPath(job,in);
        FileOutputFormat.setOutputPath(job,out);
        System.exit(job.waitForCompletion(true) ? 0 : 1);

        }
        }
